ANGULAR-RESOLVED VALENCE-BAND SPECTROSCOPY OF DIFFERENT RECONSTRUCTED3C-SIC(001) SURFACES

We present angular-resolved valence-band spectroscopy data for the (3X 2) and c(2X2) reconstructed (001) surface of cubic silicon carbide. Th e two reconstructions were prepared by annealing the sample in a flux of silicon atoms. In this way single domain reconstructed surfaces wer e achieved which was confirmed by low energy electron diffraction. The orientation of the surface unit cell with respect to the substrate or ientation excludes the alternate dimer-row model for the (3X2) reconst ruction of the surface. Angular-resolved valence-band spectra were rec orded along the [1 (1) over bar 0] direction of the sample. Both surfa ces reveal the photoemission characteristics known from angular integr ating experiments. By comparison of the reconstructions, surface deriv ed photoemission features were identified. In addition to the known V- 1 and V-2 states of the (3 x2) reconstruction, we found a surface feat ure V-3 in a limited range of the surface Brillouin zone which is to o ur knowledge reported for the first time. The results are compared to ab initio calculations of the surface band structure. The data for the c(2X2) reconstructed surface are in accordance to calculations for th e bridging dimer model. By comparing the data of the (3X2) structure t o calculations of the (2 x I) surface band structure, we found indicat ions for an assignment of the V1 and V2 states to dangling bonds and s ilicon dimers, respectively. (C) 1998 American Vacuum Society. [S0734- 2101(98)05606-1].